Random 1670 ef code.#1 wtf is ef,still fighting a cold start problem,was runningcyl contribution test and koeo test when this showed up.Ran buzz test,contrib test and they all pass I'm leaning towards a pcm/idm problem but I HATE throwing parts without knowing.00 7.3 F350 ext cab dually.

 

Clear it and see if it comes back.

 

It has shown up before,I've cleared it a couple of times but only seems to show when doing koer test.Was reading another post on the tube that runs off the exhaust could become plugged.Would this have anything to do with no start cold condition.Would like to have a conversation with someone to pinpoint my problems,I am a autotech with very little deisel knowledge and fed up with this truck I bought.I have a snap on solus pro to give data and testing,everything I've read and tested seems to be good to my knowledge.Will pay for your time if need be,would be cheaper than throwing parts and not nowing.Thanks for all the help so far!!!!Love the sight